<!DOCTYPE html>
<html>
<head>
	<meta charset="utf-8">
	<meta name="viewport" content="width=device-width, initial-scale=1">
	<title></title>
</head>
<body>

</body>
</html>

<script>
	function has(arr,team){
		for(var i=0;i<arr.length;i++){
			if(arr[i]===team){
				return true
			}
		}
		return false
	}

	document.write(has([10,20,30,"world","hello"],"hello"));
</script>